Tarra Quismundo, ABS-CBN News

SINGAPORE -- What could be the world's biggest trading bloc, which would link Southeast Asia to some of the world's largest economies, could be "substantially" complete by the end of the year, the top diplomat of this city state said Monday.

The Regional Comprehensive Economic Partnership or RCEP hopes to bring together the 10-member Association of Southeast Asian Nations with China, India, Japan, South Korea, Australia and New Zealand.

"We hope substantially to complete it by the end of the year," Singapore Foreign Minister Vivian Balakrishnan told reporters here.

"If we get that done, it will be the largest free trade agreement in the world," he said.

If completed, the RCEP will account for a third of the world's economy and half of its population, according to Bloomberg data.

Balakrishnan was optimistic coming out of discussions with fellow ministers from the region and dialogue partners here last week, where the escalating trade war between China and the US drew concern.

"I think everyone who was present there recognized that precisely because of these challenges on free trade, in the midst of a trade war, it is all the more important to make progress and in a sense raise the flag on free trade," he said.

ASEAN members need to "double down on economic integration and free trade," he said. Singapore is hosting the bloc's meetings this year.

Balakrishnan cited the importance of a multilateral approach instead of countries dealing with each other bilaterally, "where the big bully the small, the rich bully the less developed countries."

"Our economies are still developing, we still need access to markets, we still need to attract investments in order to create jobs. And, therefore, we still need a global-based system," he said.